In a bumblebee nest, a single fertile female, the queen, dominates the infertile female workers using a chemical scent – pheromone – identifying her as the egg-laying mother of them all.

Usually, all proceeds peacefully, but in some cases an intruder queen kills the nest’s matriarch and takes over.

Click on the link to read the rest of the article: How do cuckoo bumblebees trick other species? | Discover Wildlife